The Tokyo Electric Power Company, Japan's largest utility company, announced it will restart a reactor at its Kashiwazaki-Kariwa nuclear power plant on the evening of January 21. This marks the first reactor operated by the company - also referred to as TEPCO - to resume operations since the 2011 Fukushima disaster, symbolizing a significant shift in Japan's energy policy.
Bloomberg reported that TEPCO had originally planned to restart the reactor on January 20, but was forced to delay by one day due to a brief malfunction in the plant's alarm system. After inspection confirmed that the fault did not affect the nuclear reactor itself, authorities approved proceeding with the restart process.
Tokyo Electric Power will restart on January 21 a reactor at the Kashiwazaki-Kariwa nuclear power plant after inspections were completed, its first such move since the Fukushima disaster in 2011https://t.co/UAtDQ5wMih
— Reuters (@Reuters)January 21, 2026
World's Largest Nuclear Plant Returns to Service
The Kashiwazaki-Kariwa facility is considered the world's largest nuclear power plant by generating capacity. Its restart carries significant symbolic weight for both TEPCO and Japan's nuclear policy direction.
In the aftermath of the Fukushima disaster, nuclear power became heavily stigmatized in Japan, spurred on by acknowledgment from TEPCO that the plant had been inadequately prepared for the earthquake and tsunami that triggered the accident.
Japan - an energy-import-dependent nation - subsequently dramatically restructured its power generation mix by turning to imported fossil fuels and significantly expanding thermal power to maintain its supply of electricity.
Before the disaster, nuclear power accounted for about one-third of Japan's electricity generation, with plans to increase that to 50% by 2030. Currently, however, about two-thirds of Japan's 33 operable reactors remain offline.
AI and Carbon Reduction Pressures Global Nuclear Revival
Japan's nuclear restart reflects a broader global trend. As countries pursue net-zero carbon emissions targets, they are seeking stable, low-carbon electricity sources, bringing nuclear power back into favor. Simultaneously, the rapid expansion of artificial intelligence and data centers has created surging electricity demand, making upgraded nuclear facilities an attractive option for governments and corporations alike.
Major technology companies heavily investing in AI, including Microsoft and Amazon, have begun signing long-term power supply agreements directly with nuclear operators in the United States to ensure stable electricity for their AI computing operations.
Japan'sgovernment has taken a cautious approach to nuclear restarts, establishing an independent regulatory authority after the earthquake and subjecting all domestic reactors to rigorous safety reviews.
TEPCO stated that following startup, the reactor will undergo sequential control rod withdrawal tests and inspections of critical equipment, including pumps and turbines. Final regulatory approval is still required, with commercial operations expected to resume as early as late February 2026.
Kashiwazaki-Kariwa is TEPCO's only remaining commercial nuclear facility, housing seven reactors in total. While Unit 6 received initial approval for restart, Unit 7 has also obtained regulatory clearance. Whether it will be activated depends on local government decisions and public opinion. （Related： The Hidden Cost of Taiwan’s US Investment Deal ｜ Latest ）
